1. Field of the Invention
The present invention relates to a cutting method for hard, brittle materials such as ceramic, glass, concrete, stone and single crystal materials.
2. Description of the Related Art
In the past, a rotary grindstone having a rounded or rectangular edge was used for cutting completely through hard, brittle materials such as ceramic, glass, concrete, stone and Si and other single crystal materials.
For example, although a ceramic honeycomb structural body used as a catalyst support of an automobile exhaust gas purification apparatus is composed of a ceramic material such as cordierite, its manufacturing process consists mainly of forming a dried ceramic body by drying a honeycomb compact obtained by extrusion molding, cutting this to a desired length using the above rotary grindstone and finally baking. In order to increase the production efficiency of the above ceramic honeycomb structural body, it is necessary to increase the cutting speed when cutting the above dried ceramic body with a rotary grindstone.
However, as the above dried ceramic body is hard and brittle, and is chipped extremely easily, when it is cut at a high speed using a rotary grindstone having a rounded or rectangular edge, edge chipping occurs in the cut ends of the dried ceramic body being cut. Consequently, a problem arises in which the above hard, brittle material cannot be cut at high speed.
This problem is not limited to the above dried ceramic body, but also occurs similarly in the case of completely cutting through post-baking ceramics, glass, concrete, stone, single crystal materials such as Si and other hard, brittle materials, using a rotary grindstone.
One aspect of the present invention relates to a cutting method for hard, brittle materials that is capable of completely cutting through hard, brittle materials such as ceramic, glass, concrete, stone and single crystal materials without the occurrence of edge chipping and at high speed.
Another aspect of the invention relates to method for completely cutting through hard, brittle materials using a disk-shaped rotary grindstone; wherein the cross-sectional shape of the outer peripheral edge of said rotary grindstone has a roughly V-shaped pointed shape.
the cross-sectional shape of the outer peripheral edge of said rotary grindstone has a roughly V-shaped pointed shape.
In the present invention, the above rotary grindstone has a pointed shape roughly in the shape of the letter V as described above. Consequently, concentrated stress, which is generated during cutting of hard, brittle materials with a rotary grindstone, and which is applied to the cut material from the corners of the rotary grindstone and can cause the occurrence of edge chipping, can be reduced. Consequently, even in the case of cutting the above hard, brittle material at higher speeds than in the prior art, concentrated stress from the corners of the rotary grindstone that is applied to the cut material can be suppressed to below the rupture strength of the cut material. For this reason, the occurrence of edge chipping in hard, brittle materials can also be prevented when the rotary grindstone is passed through the cut material.
In this manner, the present invention is able to provide a cutting method for hard, brittle materials that is capable of completely cutting through hard, brittle materials such as ceramics, glass, concrete, stone and single crystal materials without the occurrence of edge chipping and at high speed.
Another aspect of the present invention relates to a method for completely cutting through hard, brittle materials using a disk-shaped rotary grindstone; wherein said rotary grindstone has a tapered portion on its outer peripheral edge that is inclined from a flat portion having a plane in parallel with the radial direction, and the angle of inclination of said tapered portion is 25xc2x0 or less.
The above rotary grindstone has a tapered portion in its outer peripheral edge that is inclined from a flat portion having a plane in parallel with the radial direction, and the angle of inclination of the above tapered portion is 25xc2x0 or less.
Consequently, the present invention is able to reduce the concentrated stress, when cutting hard, brittle materials with the above rotary grindstone, which is applied to the cut material from the corners of the grindstone at the boundary between the above flat portion and the above tapered portion. Consequently, as the concentrated stress that is applied to the cut material can be suppressed to below the rupture strength of the cut material even in the case of cutting the above hard, brittle materials at higher speeds than in the prior art, the occurrence of edge chipping in the hard, brittle materials can be prevented when the rotary grindstone passes through the cut material.
Thus, according to the present invention, a cutting method for hard, brittle materials is obtained that is capable of completely cutting through hard, brittle materials such as ceramic, glass, concrete, stone and single crystal materials without the occurrence of edge chipping in said hard, brittle materials and at high speed.